Zinc finger protein 544 promotes hepatocellular carcinoma by generating an immunosuppressive tumor microenvironment

BACKGROUND & AIMS: This study identified zinc finger protein 544 (ZNF544) as a biomarker in hepatocellular carcinoma (HCC) and aims to delineate its functional role. METHODS: The correlation between ZNF544 expression and clinical parameters of HCC patients (n = 50) and the malignant biological behavior of HCC cells was analyzed in vitro (n = 5/group) and in vivo (n = 10/group). RESULTS: ZNF544 was elevated in tumors of HCC patients (p = 0.0006). Patients with HCC exhibiting high ZNF544 expression had a higher clinical stage (p = 0.0026) and showed greater infiltration of M2 macrophages (p = 0.0031) and Tregs (p = 0.0094). ZNF544 knockdown inhibited the pro-angiogenic ability of HCC cells (p < 0.01). Increased ZNF544 expression accelerated the growth of orthotopic tumors (increased > 80%, p < 0.0001) and the infiltration of M2 macrophages (increased > 60%, p = 0.0008) and Tregs (increased > 80%, p = 0.0029) within the orthotopic tumors, and accelerated lung metastasis (number of mice with lung metastasis increased > 160%). ZNF544 bound to the spermatogenesis-associated serine-rich protein 2 (SPATS2) promoter and activated its transcription, whereas SPATS2 enhanced the triosephosphate isomerase (TPI1) mRNA stability. ZNF544 promoted glycolysis in HCC cells in a SPATS2-dependent manner. SPATS2 knockdown suppressed glycolysis in HCC cells and inhibited orthotopic tumor growth, which was rescued by TPI1 overexpression. Ivermectin was identified as a pharmacological inhibitor of ZNF544, effectively suppressing the progression of HCC. CONCLUSIONS: ZNF544 accelerates HCC by activating SPATS2/TPI1 and promoting glycolysis and immune escape. Targeting ZNF544, including compounds such as ivermectin, may offer a preliminary avenue for further investigation in HCC. IMPACT AND IMPLICATIONS: This research underscores the role of ZNF544-SPATS2 as a pivotal regulator of TPI1 expression in HCC. TPI1 shapes the immunosuppressive TME and accelerates growth and metastasis by promoting glycolysis and facilitating the infiltration of M2 macrophages and Tregs. Our research suggests that ZNF544 could serve as a novel biomarker for HCC, and the pharmacological inhibitor of ZNF544, ivermectin, emerges as a promising therapeutic option for HCC treatment.